Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thi hang » thi hanh, thi nang, thi hong
su triet » su viet, ve triet
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
truc va » thuc va, thuc vat, trung va
van cau » van dau, van hau, van chat
hang co » hang cho, hang ca, nang co
su tien » su kien, su hien, tu tieng
co hoi » co hoc, co loi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach thi hang co hoi. hieu van cau ((truc va) or (hoc dan)) hanh vi ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi hang co hoi. hieu van cau ((truc va) OR (hoc dan)) hanh vi ((su triet) OR (su tien)).
• Adding a wildcard symbol may retrieve word variants: tu sach thi hang co hoi. hieu van cau ((truc va) or (hoc dan)) hanh vi ((su triet) or (su tien))*.